Magneto-electric machine



' l-:.M9REL 1,810,844 v IAG'NETO ELECTIC MACHINE June 16, 1931..

Filed Nov. 7, 1928 NIV snn.

` 40 the ratio of the internal diamete Patented- '.Iune io, 1931 UNITED ,STATES EMILE MOREL, OF

' DOMENE, FRANCE v MAGNETO-ELECTRIC MACH'INE Applicatioaled November 7, .1928, Serial No. 817,829, and in Ifra'nce and Germany November 9, 1927.

This invention relates to magneto electric machines suitable for use with internal combustion engines and has for its principal object to provide a magneto of simple construc- 5 tion small bulk and great power. The problem of bulk-has become in practice one of considerable difficulty to solve without other disadvantages since engine' designers have xed very limited standard maximum d1- mensions for magneto mountings on engines.

J lThe employment of so``alled inductor magnetos i. e. magnetos with rotating magnet systems has assisted towards finding a satisfactory solution to the problem and the appearance of magnetic steels such as cobalt steel of vhigh coercive force land high remanence,` has still furtherpassisted matters.

Nevertheless; despite these advances known magnetos are still Vnot suliiciently powerful 20 and stable if of small size. y

' In one arrangement. in accordance with the present invention the magnet system is Y constructed of steel such as cobalt steel having a hi for example, in the form of a ringhaving diametrically opposedpolarities which` may be mounted on a bronze spindle and is provided with two associated polar masses of soft steel. The polar masses, which may be solid or V laminated, are in the form of portions of a l ring comprising each an' angle of about 90 degrees and are positioned on the outer sury face ofthe magnet ring opposite the magnetic poles thereof. r v

' This arrangement, however, is only fully satisfactory in certain cases, andalthough it is a considerable improveme'n known arrangements it only provides a complete solution to the problem for magnetosV in vwhich r toithe external diameter' of the annular magnet lies withincertain limits outside which the mag-- "netic flux tends to be manifested towards the interior of thermagnet ring. The fall in in- 45 tensity of magneticl field becomes considerably important when' the magnet is located and rotated in an induction electromagnetic circuit, and moreover the stability of the magnet'is sometimesnot as good as it lmight-be.`

1504 The conditions which a satisfactory induc- 4 gh coercive vforce and high remanence,

tive ring magnet must fulfill are that it'must have' a magnetic field as intense as possible both on o en and closed circuit, the said lield must be istributed as far as possible on the exterior of the magnet, the fall in field in- 554 tensity mustbe asv smallas possible when the ring is, after magnetization, located and rotated in van induction electromagnetic circuit, and the magnet must be stableboth as regards direction and intensity ofmagnetic field. In addition, of course the magnet should be of simple and robust construction.

It has now been found, asthelresult of experiment, that the fall in intensity of magnetic field increases with increase in the number of parasitic lines of force within the magnet .ring while lack of stability in the magnet is caused to a large degree by variations inintensity and direction of such parasitic lines. Further, stability is increased when the number. of parasitic lines is diminished r (even when no such diminution is.v effected) .when their direction is fixed.

In'another arrangement in accordance with the invention the bronze spindle on which the 75. i

annular magnet is mountedl is replaced byoa core of soft iron or steel, the presence of which stabilizes the interior lines efforce of the ring and thereby diminishes the fall in intensity of themagnetic field when' the magnetized 80 ring operates'as an inductor in an electromagnetic circuit and stabilizes the magnet. 'Further its employment simplies the construction of therrotating magnet and.ren ders it most robust and ofa lower cost.

vThe polar masses of the magnet may be provided with solid orv laminated projections of metal similar'v to that ofthe masses Athemselves and attached thereto or formedl as prolongations thereof, said vprojections enclosing the magnetized ring at a short distance therefrom. The extremities of the prolongations should face one anothervwithout touching in the neighbourhood of the neutral line of the polaritiesof the magnet. The said projections assure a better distribution of the iux in the ring and increase'the magnetic stability.

The invention is illustrated in the aceom- ,panying drawings in which '1 Figure 1 is a side view of one form of conthe resent invention;

ligure 2 is a section of this magnet shown in position in an inductor circuit; *t

Figure 3 is a section on line A-A of Figure 4 of a modiiied magnet; and

Figure 4 is a side view of Figure 3. Referring to Figures 1 and 2 the rotating magnet of an inductor type magneto comprises a ring 1 of steel of high coercive force and high remanence, the interior diameter of which is relatively small with respect to the exterior diameter. 2 Within the ring is an interior core 2 of soft iron or steel in close contact with ,said ring and which serves as the rotating shaft of the magnet 3, 3a are polar masses formed of solid or laminated soft iron or steel, arranged closely on the exterior surface of the magnet 1 and each sub- `tending an angle of about 90, preferably somewhat above this figure. These polar masses which are concentric with the exterior surface of the magnetized ring 1, are fixed thereto by screws, 4, 4a, which also serve/to render said polar masses solid with said ring. Obviously the screws may be replaced by a rivet passing from one polar mass to the oth er or by any other equivalent device.

A rotating magnet thusconstituted possesses a higher magnetic power with respect to its volume and gives remarkable results of stability of iield when utilized as an inductor in a.` customary electromagnetic circuit 5, 6, 5a. Owing to the. fact that the ring and polar masses are in close magnetic connection the `magnetic flux is substantially equally distributed over the whole of the exterior surface of said polar masses instead of decreasing towardsthe extremities thereof as would be the case if they were merely projections from the mass ofthe ring 1. The screws 4, 4a 4do not noticeably diminish the eifectiveness of the inductor.

In the modicat-ionshown in Figures 3 and 4 the polar masses 3, 3a are prolonged circumferentially at 7 8, 7 a, 8a, these prolongations extending around portions of the periphery of the magnetized ring 1 and being spaced at a short distance therefrom and the extremities of said prolongations being opposite one another and separated by a short distance at the neutral line of the magnet polarities. These projections are, in the construction illustrated, integral with the polar masses 3, 3a, but they may, of course, be separate members attached thereto. 'Ihe provision of such prolongations increases still further the stability of the magnet.

What I claim is 1. A magneto electric machine of the inductor type having an inductor comprising a magnetic ring of steel of high coercive force and remanence, a mounting core passing through said ring for rotating it, a plurality of polar masses of soft magnetic material attached to and in magnetic contact with the periphery of said ring so as to be magnetically connected therewith, and prolongations upon said polar masses, said prolongationsbeing spaced a short distance from said ring and partly embracing it, the extremities of the prolongations on adjacent polar masses being a small distance apart in the neighbourhood of the neutral polarities of the said ring.

2. Avmagneto electric machine of the inductor type having an inductor comprising acmagnetic ring of steel of high coercive force and remanence having an interior diameter relatively small with respect to the exterior diameter, a mounting core passing through said ring for rotating it, a pair of polar masses of soft magnetic materialattached to and in Contact with the periphery of said ring so as to be magnetically connected therewith, said polar masses being arranged diametrically opposite one another and embracing each about one quarter of the circumference of, said ring, and prolongations upon said polar masses, said prolongations being spaced a short distance from said ring and partly embracing it, the extremities of the prolongations on opposite polar masses being opposite one another and a small distance apart in the neighbourhood of the neutral line of the polarities of said ring.

3. A magneto electric machine of the inductor type having an inductor comprising a magnetic ring of cobalt steel of high coercive force and remanence having a diameter greater than its thickness,.a mounting core of soft magnetic material passing through said ring for rotating it, and a pair of polar masses of soft magnetic material closely attached to and in magnetic contact with the periphery of said ring so as to be magnetically connected therewith, said polar masses being arranged diametrically opposite one another and embracing each about one. quarter of the circumference of said ring, means extending throughout a diameter of said ring for attaching said polar masses thereto, and prolongations upon said polar masses, said prolongations being spaced a short distance from said ring and partly embracing it, the extremities of the prolongations on opposite polar masses being opposite one another and a small distance apart in the neighbourhood of the neutral line of the polarities of the said ring.

In'testimony whereof I have signed this specification. EMILE MOREL. 

